1. Field of the Invention
The invention relates to an insulating device for use in connection with high and low temperatures. Such insulating devices are applied where the objective is to keep materials or equipment at a predetermined high or low temperature.
2. Description of the Prior Art
German Published Non-Prosecuted Application (DE-OS) No. 32 35 708 discloses a thermal insulation device which is arranged around a high-temperature storage battery. Storage cells of the sodium-and-sulfur type which operate at a temperature of 350.degree. C. are in the interior of the insulation. The insulation is formed by a double-wall housing with an evacuated space between the inner and the outer housing wall which space is filled with insulating material. In the device described there, the insulating material is in the form of powder and fibers. The powdered material is preferably one or several infrared-optical opacifier 5. Borosilicate glass fibers are used as the fiber material. With this ceramic insulating material, thermal conductivities of 2 to 8 mW/(mK) can be achieved at high temperatures in a vacuum and under external atmospheric pressure.